unix_ioctl ?

From: James Stevenson (mistral@stev.org)
Date: Mon Feb 26 2001 - 08:13:24 EST


i notcied in unix_ioctl at the start of most of its functions is it
possible for the sock->sk to be NULL ?

static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long
arg) {
        struct sock *sk = sock->sk;

as there is no test to see if its null it just jumps in and uses its data
and could i thave caused this ?

ksymoops 2.3.4 on i686 2.2.18. Options used
     -V (default)
     -k /proc/ksyms (default)
     -l /proc/modules (default)
     -o /lib/modules/2.2.18/ (default)
     -m /boot/System.map (specified)

No modules in ksyms, skipping objects
Warning (read_lsmod): no symbols in lsmod, is /proc/modules a valid lsmod file?
Unable to handle kernel NULL pointer dereference at virtual address 000001c4
current->tss.cr3 = 01f00000, %cr3 = 01f00000
*pde = 00000000
Oops: 0000
CPU: 0
EIP: 0010:[<c01880c3>]
Using defaults from ksymoops -t elf32-i386 -a i386
EFLAGS: 00010202
eax: c18e0684 ebx: 00000000 ecx: 00000168 edx: bfffee9c
esi: c18e0640 edi: bfffee9c ebp: 0000541b esp: c1ef3f80
ds: 0018 es: 0018 ss: 0018
Process gnome-terminal (pid: 888, process nr: 47, stackpage=c1ef3000)
Stack: c0162d81 c17614e0 0000541b bfffee9c c1713980 c012d7bd c1761440 c1713980
       0000541b bfffee9c c1ef2000 00000000 00000000 bfffee58 c18e7e40 c1761440
       c0109374 00000004 0000541b bfffee9c 00000000 00000000 bfffee58 00000036
Call Trace: [<c0162d81>] [<c012d7bd>] [<c0109374>] [<c010002b>]
Code: 8b 59 5c 8b 44 24 14 89 da e8 73 e9 04 00 eb 06 90 b8 ea ff

>>EIP; c01880c3 <unix_ioctl+57/70> <=====
Trace; c0162d81 <sock_ioctl+1d/24>
Trace; c012d7bd <sys_ioctl+1a1/1bc>
Trace; c0109374 <system_call+34/38>
Trace; c010002b <startup_32+2b/11e>
Code; c01880c3 <unix_ioctl+57/70>
00000000 <_EIP>:
Code; c01880c3 <unix_ioctl+57/70> <=====
   0: 8b 59 5c mov 0x5c(%ecx),%ebx <=====
Code; c01880c6 <unix_ioctl+5a/70>
   3: 8b 44 24 14 mov 0x14(%esp,1),%eax
Code; c01880ca <unix_ioctl+5e/70>
   7: 89 da mov %ebx,%edx
Code; c01880cc <unix_ioctl+60/70>
   9: e8 73 e9 04 00 call 4e981 <_EIP+0x4e981> c01d6a44 <__put_user_4+0/18>
Code; c01880d1 <unix_ioctl+65/70>
   e: eb 06 jmp 16 <_EIP+0x16> c01880d9 <unix_ioctl+6d/70>
Code; c01880d3 <unix_ioctl+67/70>
  10: 90 nop
Code; c01880d4 <unix_ioctl+68/70>
  11: b8 ea ff 00 00 mov $0xffea,%eax

1 warning issued. Results may not be reliable.


Check Out: http://stev.org
E-Mail: mistral@stev.org
  1:10pm  up 24 days, 20:55,  7 users,  load average: 2.10, 1.36, 1.09

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

This archive was generated by hypermail 2b29 : Wed Feb 28 2001 - 21:00:11 EST